Coventry airport was burning £5m per year i.e it cost £10m to make £5m income. That is why it owed £25m when it was wound up.
The big question is at what levels of turnover and type of operations do the running costs get covered by the income? If they want a full service (>£6m cost) then they need a large income that will be hard to get. A very small operation (~£1m) the income would not even cover the fixed costs. They need look at the buisness case for a few million a year operation that has more income than cost.